1. Spotting distant planets that may sustain life will require a telescope larger than anything currently available. When it starts operation in the early 2020s, the European “Extremely Large Telescope”, with a mosaic mirror more than 39m across, will target for observation planets of similar size to Earth that are orbiting stars much like our Sun.
2. Because of the obvious dangers, Professor Rees says spaceflight should not be billed as “tourism” in the style of Sir Richard Branson’s Virgin Galactic. However, he believes five-day trips taking paying customers around the Moon are likely within a decade. Round trips to Mars, taking about 500 days, are the next step, as recently proposed by the US tycoon Dennis Tito.
3. By the end of the 21st century tiny flotillas of robotic space exploration craft, aided and abetted by the successors to the Hubble Telescope, will map the entire Solar System – planets, moons and asteroids – initially with a view to the possible exploitation of minerals.
4. Don’t expect mass emigration any time soon – our universe is too inhospitable. However, in a century or more, colonies of adventurous humans are likely to be living independently from the Earth – either on asteroids or on Mars.
5. The time needed to travel to nearby stars will far exceed a human lifespan. Interstellar travel, therefore, will only be an option for what Prof Rees calls “post-humans”, who evolve (not by natural selection, but by design) to cope with hibernation or suspended animation.
6. Hypercomputers will have the power to simulate living organisms – perhaps even entire worlds or “virtual universes”, incorporating artificial life. This would then allow for a new kind of “virtual time-travel”.